Technical Field
Embodiments described herein are related to the field of integrated circuits, and more particularly to the implementation of energy monitoring circuits.
Description of the Related Art
Computing systems may include one or more systems-on-a-chip (SoCs), which may integrate a number of different functions, such as, application execution, graphics processing and audio processing, onto a single integrated circuit. With numerous functions included in a single integrated circuit, chip count may be kept low in mobile computing systems, such as tablets, for example, which may result in reduced assembly costs, and a smaller form factor for such mobile computing systems.
Various computing systems may include one or more power sources, such as batteries for example, for supplying power to some or all of the system. For various reasons, a current provided by one or more of the power sources (i.e., a supply current) may be monitored within the system. Supply currents may be monitored, for example, to track and compare power consumed by one or more portions of the computing system, to estimate a remaining power available from the power source, or to profile energy usage over time. A battery management circuit (BMC) or other type of integrated circuit (IC) may be used to monitor supply currents. During times when the computing system is inactive and not consuming significant power, the BMC may be placed in a reduced power mode. However, in some embodiments, the BMC may not enter a reduced power mode unless it can respond quickly when the computing system moves into an active state. This restriction may prevent use of some reduced power modes in such embodiments. Alternatively, accuracy may be lost if the BMC is placed in a reduced power mode as the computing system may begin consuming non-trivial amounts of power from the battery before the BMC is able to return to an operating state capable of monitoring the increased power consumption.